SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '42cf60317f5edcb57edd44008dc4424a5a077518b54fd90aa2a5edb1373243e3' 
  AND token = 'PqszQ6KT9IUDRZSDy2HojnavSAiSfNgn+Ji2koFTrpI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}